| 摘要 |
<p>An orifice plugging sensor for a flow-rate controller having an orifice, comprising a memory (M) in which is stored reference pressure decrease data Y(t) about the upstream-side pressure P1 measured when the flow rate is changed from a high preset flow rate QSH to a low preset flow rate QSL under the condition that an orifice (2) does not plug, a pressure sensor (14) for measuring pressure decrease data P(t) about the upstream-side pressure P1 measured when the flow rate is changed from the high preset flow rate QSH to the low preset flow rate QSL under the condition that the orifice is in an actual state, a central processing unit (CPU) for comparison operation of the pressure decrease data P(t) and the reference pressure decrease data Y(t), and an alarm circuit (46) for giving an alarm of a plugging when the pressure decrease data P(t) differs from the reference pressure decrease data by a predetermined degree.</p> |
